When a Governor requests Federal assistance in responding to a major disaster or emergency (as those terms are defined in section 102 of the Robert T. Stafford Disaster Relief and Emergency Assistance Act (42 U.S.C. 5122)), the Secretary of Defense may, without the consent of the member affected, order any unit, and any member not assigned to a unit organized to serve as a unit, of the Army Reserve, Navy Reserve, Marine Corps Reserve, and Air Force Reserve to active duty for a continuous period of not more than 120 days to respond to the Governor’s request.

Members ordered to active duty under this section shall not be counted in computing authorized strength of members on active duty or members in grade under this title or any other law.

Whenever any unit or member of the reserve components is ordered to active duty under this section, the service of all units or members so ordered to active duty may be terminated by order of the Secretary of Defense or law.